BS 13443-1:2002 pdf download – Water conditioning equipment inside buildings — Mechanical filters — Part 1: Performance rating 80 ?m to 150 ?m — Requirements for performances, safety and testing
5 Materials (Chemical and hygienic behaviour of materials) The selection of materials shall be the responsibility of the manufacturer, provided that the complete filter satisfies the requirements of EN 1 567.
NOTE The materials and coatings used should not contaminate or change the drinking water, when in normal or accidental contact up to the maximum designed temperature. The requirements , with regard to the effects of materials on drinking water quality, are specified in national regulations. The manufacturer shall state in his technical literature what materials and coatings are used. The materials, in particular copper alloys, shall conform to relevant national standards or recommendations. These references shall be stated. Copper-zinc alloys containing more than 1 0 % zinc are subject to dezincification when submitted to water capable of dezincification.
In countries where the use of products made of dezincification resistant material is required, the product have to guarantee a dezincification depth less than 200 µm in any direction. They have to be tested and marked in accordance with EN ISO 6509 and have to be marked in compliance with the indications under clause 9 of the present standard.
6 General design requirements
6.1 Backwashable filters Backwashable filters shall be able to be cleaned without the aid of tools. No substances shall be allowed to penetrate into the drinking water supply as a result of the cleaning operation. After completion of backwashing, the original grade of filtration and pressure drop shall be recovered. Backwashable filters shall be provided with a backwash water outlet, conforming to EN 1 71 7. It shall be possible to clean the filter mounted in any of the positions specified by the manufacturer with no interruption of filtered water supply during backwashing.
6.2 Single-use filters Single use filters shall be designed in such a way that the filter elements can be replaced without any risk of contamination of the drinking water. It shall be possible to replace the filter mounted in any of the positions specified by the manufacturer. Any tools used in this process shall not come into contact with drinking water and shall be provided by the manufacturer. If specific tools are necessary they shall be supplied by the manufacturer. Replacement filter elements shall be single packaged to prevent contamination from outside.
6.3 Thermal stability Filters shall be designed to withstand room and water temperatures of at least 30°°C.
7 Performances requirements
7.1 Bending Strength of the body When subjected to a bending moment in accordance with 8.2.1 .2, there shall be no permanent deformation, fissures or ruptures.
7.2 Pressure Strength of the Filter Housing When subjected to a hydraulic test as defined in 8.2.2, there shall be no visible leakage or permanent deformation.
7.3 Pressure Strength of the Filter Element After being subjected to a differential pressure as described in, there shall be no visible deformation of the filter cartridge.
7.4 Dynamic Pressure Test While subject to cyclic pressure test as described in 8.2.4 the filter hosing shall show no visible signs of leakage or permanent deformation.
7.5 Pressure Drop When subjected to the nominal flow rate as described in 8.3.1 .2, the filter, with a clean element, shall not develop a pressure drop higher than 50 kPa.
7.6 Filter Surface Velocity The filter surface velocity shall not exceed 0,1 5 m 3 /(h cm 2 ) for backwashable filters and 0,025 m 3 /(h cm 2 ) for replaceable cartridge filters at the nominal flow rate. 7.7 Filtration Rating When tested in accordance with 8.4.2, the maximum filter rating shall be between 1 00 micrometres (µm) and 1 50 micrometres (µm) and the minimum filter rating shall be between 80 micrometres (µm) and 1 20 micrometres (µm).
8 Performance tests
8.1 Test Conditions Tests shall be carried out with the filter in the horizontal position, except for special models. Unless otherwise specified tolerances shall be ± 5%. Unless otherwise stated tests shall be carried out at room temperature with water between 1 0 °C and 30 °C. If the designed water temperature is higher than 30 °C, the designed temperature shall be used for the test.
8.2 Mechanical Performance
8.2.1 Bending strength of the body Principle The mechanical bending strength of the body is tested by a bending moment test, in which a force is applied for a predetermined period.